Faculty Collaboration Database

Characterization of sinoatrial node in four conduction system marker mice. J Mol Cell Cardiol 2007 May;42(5):946-53

Date

04/27/2007

Pubmed ID

17459410

Pubmed Central ID

PMC1936434

DOI

10.1016/j.yjmcc.2007.02.008

Scopus ID

2-s2.0-34247857520 (requires institutional sign-in at Scopus site)   21 Citations

Abstract

The specialized cardiac conduction system (CCS) consists of the sinoatrial node (SAN) and the atrioventricular (AV) conduction system (AVCS), which includes proximal (AV node, bundle of His and bundle branches) and distal (Purkinje fibers) components. In four CCS marker mice [two transgenic (cGATA6|lacZ, CCS|lacZ) and two targeted gene knock-in (minK|lacZ, Hop|lacZ)] the expression of the lacZ gene (beta-gal) has been reported to mark portions of the proximal and distal AVCS; the expression of this marker in the adult SAN is unknown. The primary objective of this study was to analyze the utility of these marker mice in the identification of the SAN. Intercaval and interventricular septal regions, containing all the components of the CCS, were freshly dissected from adult mice based on the anatomical landmarks and sectioned. Immunohistochemical characterization was performed with SAN markers (Cx45, HCN4), compared to the reporter expression (beta-gal) and markers of the working myocardium (Cx40 and Cx43). In all four of the CCS marker mice, we found that beta-gal expression is consistently observed in the proximal and distal AVCS. However, the presence of lacZ gene expression in the working myocardium outside the CCS and/or the absence of this reporter expression in the SAN prevent the effective use of these mice to identify the SAN, leading us to conclude that none of the four CCS marker mice we studied specifically mark the SAN.

Author List

Viswanathan S, Burch JB, Fishman GI, Moskowitz IP, Benson DW

MESH terms used to index this publication - Major topics in bold

Animals
Atrioventricular Node
Connexins
Female
GATA6 Transcription Factor
Heart Conduction System
Lac Operon
Male
Mice
Mice, Transgenic
Potassium Channels, Voltage-Gated
Sinoatrial Node